Two pregnancies and the loss of the 46,XX cell line in a 45,X/46,XX Turner mosaic patient.

Two successful pregnancies in a patient with a 45,X karyotype are reported. Twelve pregnancies have been reported in 9 monosomy X patients and 57 pregnancies in 24 patients with both a 45,X and a 46,XX cell line. The patient reported here was diagnosed at 10 years of age as a Turner mosaic (45,X/46,XX), but showed no evidence of a normal cell line in any of the four tissues analyzed 15 years later. The difficulty in detecting mosaicism as well as the stability of autosomal and sex chromosomal mosaicism are discussed. An argument is made for early cytogenetic evaluation, utilizing multiple tissues, and analyzing an adequate number of cells.